push_to_nsidc.py: add usage
push_to_nsidc.py: add usage

oleg-alexandrov/StereoPipeline,NeoGeographyToolkit/StereoPipeline,ScottMcMichael/StereoPipeline,ScottMcMichael/StereoPipeline,NeoGeographyToolkit/StereoPipeline,ScottMcMichael/StereoPipeline,ScottMcMichael/StereoPipeline,NeoGeographyToolkit/StereoPipeline,oleg-alexandrov/StereoPipeline,ScottMcMichael/StereoPipeline,oleg-alexandrov/StereoPipeline,oleg-alexandrov/StereoPipeline,oleg-alexandrov/StereoPipeline,NeoGeographyToolkit/StereoPipeline,ScottMcMichael/StereoPipeline,NeoGeographyToolkit/StereoPipeline,oleg-alexandrov/StereoPipeline,NeoGeographyToolkit/StereoPipeline